The present invention relates generally to a grade control alignment device and more particularly to a grade control alignment device used in combination with a machine having an automatic grade control system to control the grade or elevation of a working implement.
In the construction industry various machines are available which cut or fill material to a predetermined grade or elevation. These machines incorporate devices which automatically control the grade and slope of a working implement by contact of a sensor wand with a preset string line or grade reference line. One such machine for the simultaneous and continuous preparation of a graded surface and the slip forming of a concrete structure on the prepared surface is disclosed in U.S. Pat. No. 3,779,661.
One of the most critical problems associated with these machines having automatic grade controls, is the variation from the desired grade or elevation which is encountered in use. It is extremely important to minimize this variation where strict specifications must be adhered to. Variations from the required grade of a prepared surface or variations from the required grade of asphalt or concrete applied over a prepared surface, can result in an applied surface which is either too thick or too thin. If the applied surface is too thick, expensive materials are unnecessarily used; if the applied surface is too thin, minimum specifications will not be met. In order to insure that grade variations are minimized, contractors commonly have laborers follow behind the machines to manually check the grade with a string line and inform the machine operator of needed adjustments. This procedure is, likewise, economically wasteful. Those concerned with this problem recognize the need for an improved means and method for controlling the grade of a working implement.